High energy gamma ray observatories for the study of cosmic ray electrons above 1014 eV

Abstract

Abstract We have studied in detail the possibility of detecting cosmic ray electrons of energy ≳10 14 eV using high energy γ-ray detectors. Such instruments would detect synchrotron γ-rays radiated by the electrons, while traversing the Earth's magnetic field. These radiated γ-rays are expected to be incident along a straight line in the detector for an unambiguous identification of an electron event. Our analysis shows that small γ-ray detectors such as those in SAS-2 and COS-B satellites cannot be used for this purpose. The high energy γ-ray detector to be flown on the GRO satellite may be able to detect electrons, if the energy spectrum of electrons at high energies is modified by the influence of a nearby source. Such exciting possibilities can be observed with large area γ-ray instruments, which are aslo capable of detecting γ-rays through Compton scattered electrons. We have, in this investigation, suggested ways of utilizing future large area γ-ray observatories to open up a new avenue for the study of ultra high energy cosmic ray electrons.